Golf Club Shaft

ABSTRACT

It is object of the present invention to provide a golf club shaft superior in accuracy, minimizing a displacement between thermosetting resin layers, capable of obtaining a feeling close to the feeling of a steel shaft, and superior in stability. 
     To solve the above problems, a golf club shaft of the present invention uses a golf club shaft comprising a torsional rigidity holding layer made of thermosetting resin including reinforcing fibers diagonally crossed in the longitudinal direction of said shaft and a UD flexural rigidity holding layer made of thermosetting resin including reinforcing fibers aligned in parallel to the longitudinal direction of said shaft, characterized in that at least a part of said torsional rigidity holding layer includes a plain weave fabric layer obtained by winding and curing like a shaft-shape a plain weave prepreg which lets a plain weave fabric having mutually woven warps and wefts impregnate with thermosetting resin in such a way that said warps and wefts are diagonally crossed in the longitudinal direction of said shaft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a golf club shaft, more particularly toa golf club shaft having a feeling similar to the feeling of a steelshaft and being superior in stability.

2. Prior Art

FIG. 8 is a perspective view showing a configuration of a conventionalplastic golf club shaft. As shown in FIG. 8, the golf club shaft has astructure having a torsional rigidity holding layer 1 in whichreinforcing fibers are diagonally crossed, a flexural rigidity holdinglayer 2 in which reinforcing fibers are aligned in a direction parallelwith the longitudinal direction of the shaft, and optionally acompressive rigidity holding layer 3 in which reinforcing fibers arealigned in the direction vertical to the longitudinal direction of theshaft. Typically, the golf shaft is formed by 4 to 6 plies of thetorsional rigidity holding layer 1 and 4 to 6 plies of the flexuralrigidity holding layer 2 (e.g. Specification of Japanese PatentApplication No. 311678/1995).

In the case of a conventional plastic shaft, optionally a prepreg inwhich reinforcing fibers are aligned in the direction vertical to thelongitudinal direction of the shaft is wound on a tapered shaft-likemetallic mandrel. Thereafter, a prepreg sheet 4 in which reinforcingfibers are diagonally crossed is wound on the above mentioned prepreglayer. As shown in FIG. 9, the prepreg sheet 4 is made such thatoverlapping a titled prepreg 41 in which reinforcing fibers such ascarbon fibers are diagonally set in a predetermined direction with anincline prepreg 42 in which reinforcing fibers are set in the directionopposite to the predetermined direction. Then a prepreg sheet in whichreinforcing fibers are set in the direction parallel with thelongitudinal direction is wound on the prepreg sheet 4, then a tape isspirally wound on the prepregs for setting, and a thermosetting resincontained in the prepreg sheets is thermally cured. Hereafter, a prepregin which reinforcing fibers are aligned in the uni-direction is referredto as a UD prepreg. In this case, the concept of the UD prepreg includesnot only the prepreg in which reinforcing fibers are aligned in adirection parallel with and vertical to the longitudinal direction ofthe shaft but also the incline prepreg 41 in which reinforcing fibersare set on a slant to a predetermined direction and the titled prepreg42 in which reinforcing fibers are set the direction opposite to thepredetermined direction.

In the case of the golf club shaft manufactured in accordance with theabove method, a tape trace for setting is formed on the surface of theshaft. Therefore, the shaft is formed into a product by polishing thesurface of the above outermost-surface flexural rigidity holding layer,removing the tape trace and smoothing the surface, applying painting andprinting to the surface, and then forming a transparent surface layer.

The above plastic shaft is basically manufactured by curingthermosetting resin contained in the UD prepreg layer in whichreinforcing fibers are aligned in one direction as described above.However, though a reinforcing fiber (in the case of carbon fiber) has anelongation of 1.5%, a plurality of thermosetting resin layers has asmall strength and a large flexibility compared to the reinforcingfiber. Therefore, the thermosetting resin layer shows a sufficienteffect in the direction in which reinforcing fibers are aligned.However, it has a problem that a deformation or displacement occursbetween thermosetting resin layers when a force is applied in thethickness direction or transverse direction. When taking a shot by aclub using the golf shaft manufactured as described above, a problemoccurs that a stable shot cannot be easily taken due to a displacementor deformation between thermosetting fiber layers. Therefore, afluctuation may occur in direction and carry. Moreover, the abovedisplacement between thermosetting resin layers may deteriorate thefeeling of a shot. That is, though a golf senior tends to like thefeeling of a steel shaft, the above displacement between thermosettingresin layers has a problem that it causes a feeling separate from thefeeling of a steel shaft.

Moreover, the torsional rigidity holding layer 1 is formed by adheringthe UD prepregs 41 and 42. So it has a problem that accuracy of shaft isnot improved due to a displacement for laminating the prepregs.Furthermore, because laminating is performed, a problem occurs that thenumber of steps increases and the workability is deteriorated.Hereafter, the above torsional rigidity holding layer is referred to asa UD torsional rigidity holding layer.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a golf club shaftrequiring a less number of steps, superior in workability, and capableof being easily manufactured. It is another object of the presentinvention to provide a golf club shaft superior in accuracy, minimizinga displacement between thermosetting resin layers, capable of obtaininga feeling close to the feeling of a steel shaft, and superior instability.

SUMMARY OF THE INVENTION

To solve the above problems, a golf club shaft of the present inventionuses a golf club shaft comprising a torsional rigidity holding layermade of thermosetting resin including reinforcing fibers diagonallycrossed in the longitudinal direction of said shaft and a UD flexuralrigidity holding layer made of thermosetting resin including reinforcingfibers aligned in parallel to the longitudinal direction of said shaft,characterized in that at least a part of said torsional rigidity holdinglayer includes a plain weave fabric layer obtained by winding and curinglike a shaft-shape a plain weave prepreg which lets a plain weave fabrichaving mutually woven warps and wefts impregnate with thermosettingresin in such a way that said warps and wefts are diagonally crossed inthe longitudinal direction of said shaft.

Moreover, a golf club shaft of the present invention uses a golf clubshaft comprising a torsional rigidity holding layer made of athermosetting resin including reinforcing fibers diagonally crossed inthe longitudinal direction of the shaft and a flexural rigidity holdinglayer made of a thermosetting resin having reinforcing fibers aligned inthe longitudinal direction of the shaft, characterized in that thetorsional rigidity holding layer has a plain weave fabric layer formedby winding a prepreg obtained by impregnating a plain weave fabrichaving mutually woven warps and wefts with a thermosetting resin like ashaft so that the warps and wefts are diagonally crossed in thelongitudinal direction of the shaft and curing the prepreg and atriaxial fabric layer formed by winding a prepreg obtained byimpregnating a triaxial fabric having first warps inclined from weftsand second warps diagonally crossing with the warps with a thermosettingresin like a shaft, in which these wefts and first and second warps arewoven by alternately passing through upsides and downsides of yarns sothat the wefts become parallel with or vertical to the longitudinaldirection of the shaft and curing the prepreg.

According to the first inventions of the present invention, a torsionalrigidity holding layer includes a plain weave fabric layer thermallycured thermosetting resin impregnated to a plain weave fabric. The plainweave fabric is woven by warps and wefts and movements of yarns arerestricted. Therefore, a warp exerts a drag against a longitudinal forceand a weft exerts a drag against a transverse force. Therefore, it ispossible to effectively restrain a deformation of or displacementbetween thermosetting resin layers. Therefore, advantage can be obtainedthat since it is possible to restrain a displacement between layers atthe time of a shot, there are improved stabilities of distance anddirection. Another advantages can be given that a soft feeling isobtained compared to the case of only a triaxial fabric layer, return ofbowing becomes slow, and a hitting easiness is improved. Thesecharacteristics are the most suitable for an iron club including aputter.

Moreover, the second invention of the present invention uses a plainweave fabric layer formed by impregnating a plain weave fabric with athermosetting resin and curing the thermosetting resin and a triaxialfabric layer using a triaxial fabric as a torsional rigidity holdinglayer. Because the plain weave fabric and triaxial fabric arerespectively woven by warps and wefts and movements of yarns arerestricted. Therefore, it is possible to effectively restrain adeformation of or a displacement between thermosetting resin layers.Moreover, because it is not necessary to adhering the prepreg 41 withthe prepreg 42, it is possible to manufacture a golf club shaftrequiring a less number of steps and having high workability andaccuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a golf shaft of an embodiment of thepresent invention;

FIG. 2 shows a top view and a sectional view of a plain weave fabricused for a golf club shaft of the present invention;

FIG. 3 is a sectional view of a golf club shaft of an embodiment of thepresent invention;

FIG. 4 is a sectional view of a golf club shaft of another embodiment ofthe present invention;

FIG. 5 is a sectional view of a golf club shaft of still anotherembodiment of the present invention;

FIG. 6 is a sectional view of a golf club shaft of still anotherembodiment of the present invention;

FIGS. 7 a and 7 b are illustrations for explaining a configuration of atriaxial fabric,

FIG. 8 is an illustration showing a typical structure of a plastic golfclub shaft; and

FIG. 9 is a block diagram of a UD prepreg forming a conventionaltorsional rigidity holding layer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of a golf club shaft of the present invention has astructure in which the UD flexural rigidity holding layer 2 made of athermosetting resin having reinforcing fibers aligned in parallel withthe longitudinal direction of the shaft and the UD compressive rigidityholding layer 3 of a resin layer having reinforcing fibers optionallyaligned in the direction vertical to the longitudinal direction of theshaft are formed on the torsional rigidity holding layer 1 made of athermosetting resin having reinforcing fibers diagonally crossed in thelongitudinal direction of the shaft the same as the case of FIG. 8. Thegolf shaft is constituted by 4 to 6 plies of the UD flexural rigidityholding layer 1

In the case of the above embodiment of the present invention, the plainweave fabric layer 11 formed by curing a plain weave prepreg obtained byimpregnating a plain weave fabric with a thermosetting resin is used forat least a part of the torsional rigidity holding layer 1. FIG. 1 showsa preferred embodiment having the above configuration, in which theplain weave fabric layer 11 is formed on the UD torsional rigidityholding layer 1 and moreover, the UD flexural rigidity holding layer 2is formed on the layer 11.

FIG. 2 a is a top view of a plain weave fabric used for the presentinvention and FIG. 2 b is a sectional view of the fabric. As shown inFIGS. 2 a and 2 b, the plain weave fabric 5 has a structure in which awarp 51 and weft 52 are mutually orthogonal to each other and woven.Moreover, the plain weave fabric prepreg is wounded on the mandrel likea shaft and cured so that the warp 51 and weft 52 are mutually crossedat an angle θ of approx. 45° from the longitudinal direction of theshaft. In this case, then angle between the warp 51 and weft 52 on onehand and the axis line of the longitudinal direction may be slightlydeviated from 45° depending on winding, the warp 51 and weft 52 arestable because the angle formed between the warp 51 and weft 52 is 2θ,that is, 90°. Therefore, the effect for the torsion of reinforcingfibers become constant and thus, a balance is easily realized even ifthe warp 51 and weft 52 are not accurately wound. Therefore, theflexibility for design increases and the workability of the shaft isimproved. Moreover, when an angle of diagonally crossed reinforcingfibers is 45° from the longitudinal direction of the shaft, it ispossible to display the best torsional effect. Therefore, it ispreferable to wind a prepreg so that reinforcing fibers mutually become45° in the longitudinal direction of the shaft as described above.

In the case of a preferable embodiment of the present invention, a yarnof the plain weave fabric uses a carbon fiber. In the case of anotherembodiment of the present invention, the warp 51 and weft 52 can usealumina fiber, aramid fiber, silicon carbide fiber, amorphous fiber, orglass fiber. That is, the kind of a yarn is not basically restricted.

In the case of an embodiment of the present invention, it is preferablethat the thread count of the above plain weave fabric is 4 yarns/cm ormore. When the thread count is less than 4 yarns/cm, the thickness ofthe plain weave fabric increases and the workability may bedeteriorated.

Moreover, it is preferable that the thickness of a yarn is 3 K (1 Kdenotes 1,000 filaments) or less. When the thickness exceeds 3 K, 1 plybecomes too thick and it may not be possible to secure a sufficientfiber density (thread count) and the workability may be deterioratedbecause the yarn cannot be easily wound on a shaft.

In the case of the present invention, it is possible to basically useany kind of resin for the resin of a prepreg to be impregnated in theabove fabric in the case of the present invention. For example, it ispossible to use epoxy resin, unsaturated polyester resin, phenol resin,vinylester resin, or peak resin.

It is preferable that the above prepreg has a thickness of 0.3 mm orless. When the thickness exceeds 0.3 mm, 1 ply becomes too thick andthus, it may not be possible to secure a sufficient fiber density(thread count) or the workability may be deteriorated because theprepreg cannot easily be wound on a shaft.

Moreover, it is preferable that the prepreg has a weight of 400 g/m² orless. When the weight exceeds 400 g/m², it may become too thick. It ispreferable that the resin quantity of the prepreg ranges between 25 and40 wt %. When the resin quantity is 25 wt % or less, it may not bepossible to manufacture a preferable shaft because the resin quantity istoo little. However, when the resin quantity exceeds 40 wt %, the torquemay become too large when the weight of the shaft is not changed. Inthis specification, torque shows a torsion degree when one feet·pound isloaded on the rotational direction of the shaft.

In the case of an embodiment of the present invention, the UD flexuralrigidity holding layer 2 in which the reinforcing fibers in which thereinforcing fibers are aligned in the longitudinal direction of a shaftis formed on the torsional rigidity holding layer 1 (plain weave fabriclayer 11) which is a resin layer in which the reinforcing fibers form aplane weave fabric as shown in FIG. 8. A prepreg used for thecompressive rigidity holding layer 3 can be a UD compressive rigidityholding layer using a conventional UD prepreg. The UD flexural rigidityholding layer 2 constitutes the outermost surface layer of the shaft.The shaft is fanned into a product by setting the UD flexural rigidityholding layer 2, polishing the surface of the UD flexural rigidityholding layer 2 serving as the outermost surface layer and smoothing thesurface, and then applying painting and printing to the layer 2, andfinally forming a transparent surface layer on the layer 2.

Moreover, in the case of still another embodiment, it is possible toform the compressive rigidity holding layer 3 which is a resin layer inwhich reinforcing fibers are aligned in the direction vertical to thelongitudinal direction of a shaft (circumferential direction of shaft)at the inside or outside of the torsional rigidity holding layer 1 (UDtorsional rigidity holding layer 10 and/or plain weave fabric layer 11).A prepreg used for the compressive rigidity holding layer 3 can also bea UD compressive rigidity holding layer using a conventional UD prepreg.

Furthermore, in the case of still another embodiment, it is possible tolaminate the UD torsional rigidity holding layer 10 formed by aconventional UD prepreg at the outside of the above plain weave fabriclayer in order to adjust shaft characteristics such as the hardness,kick point, weight, and torsional rigidity of a shaft. In the case ofstill another embodiment, it is possible to use the flexural rigidityand/or compressive rigidity holding plain-weave fabric layer formed bycuring a plain weave prepreg obtained by impregnating the plain weavefabric with a thermosetting resin. In this case, the flexural rigidityand/or compressive rigidity holding plain-weave fabric layer ismanufactured by winding a prepreg so that the warp 51 or weft 52 becomesparallel with the longitudinal direction of a shaft and curing theprepreg. In this case, the wefts 52 (warps 51) aligned in parallel withthe longitudinal direction of the shaft contribute to flexural rigidityholding and the wefts 52 (warps 51) vertical to the warps 51 are woundin the direction vertical to the longitudinal direction of the shaft(circumferential direction). Therefore, the wefts 52 contribute tocompressive rigidity holding. In this case, it may be possible to obtainthe same advantage without forming the compressive rigidity holdinglayer 3.

When using the above plain weave fabric layer, the UD flexural rigidityholding layer 2 which is a resin layer in which reinforcing fibers arealigned in the longitudinal direction of a shaft or a resin layer notincluding reinforcing fibers are formed as an outermost surface layer.When the UD flexural rigidity holding layer 2 or the resin layer notincluding reinforcing fibers is not formed but the fabric layer ispresent at the outermost surface, fibers of the fabric layer are cut andthe function of the fabric layer is deteriorated because the surface ofthe manufactured shaft is smoothly polished.

In the case of the present invention, it is enough that there are atorsional rigidity holding layer of a plain weave fabric layer and aflexural rigidity holding layer or resin layer not including reinforcingfibers which are formed on the outermost surface. Another configuration,it is possible to variously combine a normal torsional rigidity holdinglayer and a flexural rigidity holding and compressive rigidity holdingplain-weave fabric layers as described above.

Moreover, in the case of the present invention, it is allowed to form atriaxial fabric layer together with the above plain weave fabric layers.As a typical configuration of a shaft of the present invention, the UDcompressive rigidity holding layer 3 (may be referred to as 90° layer)of a resin layer including the reinforcing fibers optionally aligned inthe direction vertical to the longitudinal direction of the shaft isformed {e.g. one layer (1 ply)} on the UD torsional rigidity holdinglayer 10 formed by curing a plurality of thermosetting resin layers of aUD prepreg sheet (e.g. four layers; in this case, UD prepreg sheet isformed by 2×4 plies) in which reinforcing fibers are diagonally crossedobtained by overlapping the incline prepreg 41 in which reinforcingfibers are diagonally set in a predetermined direction and the inclineprepreg 42 in which reinforcing fibers are set in the direction oppositeto the predetermined direction as shown in FIG. 3. The torsionalrigidity holding layer 1 formed by the plain weave fabric layer 11 isformed on the UI) compressive rigidity holding layer 3. It is allowed touse one or more plain weave fabric layers 11 (e.g. three layers).

The triaxial fabric layer 12 is further formed on the laminated layerthrough or not through one or more UD flexural rigidity holding layers 2(may be referred to as 0 layer or layers) formed by curing athermosetting resin layer including reinforcing fibers aligned inparallel with the longitudinal direction and moreover, one or more UDflexural rigidity holding layer 2 or layers 2 of 0° layer or layers isor are formed.

As shown in FIGS. 7 a and 7 b, the triaxial fabric layer 12 has a firstwarp 52 inclined from a weft 51 and a second weft 53 diagonally crossedwith the weft 52 and these weft 51, warp 52, and warp 53 are woven byalternately passing through upsides and downsides of yarns and woundlike a shaft so that the weft 51 becomes parallel (0° directional) withor vertical (90° directional) to the longitudinal direction of theshaft.

FIG. 4 shows still another preferred embodiment. In the case of thisembodiment, one or two UD torsional rigidity holding layer or layers 2or one or two UD compressive rigidity holding layer or layers 3 (0° or90° layer or layers) is or are laminated on the UD torsional rigidityholding layers (e.g. four layers; in this case, prepreg sheet is formedby 2×4 plies) 1 formed by mutually overlapping an incline prepreg 41 inwhich reinforcing fibers are diagonally set in a predetermined directionand an inclined prepreg 42 in which reinforcing fibers are set in thedirection opposite to the predetermined direction and curing a pluralityof thermosetting resins of the UD prepreg sheet 4 in which reinforcingfibers are diagonally crossed. It is possible to replace the UDtorsional rigidity holding layer 10 and the UD flexural rigidity holdinglayer 2 or UD compressive rigidity holding layer 3 (0° layer or 90°layer). That is, it is allowed to first form the 0° layer or 90° layerand then form the UD torsional rigidity holding layer 10.

Torsional rigidity holding layers (e.g. two or three layers)respectively formed by the plain weave fabric layer 11 are formed on theabove layer, a triaxial fabric layer 12 is formed on the plain weavefabric layer 11 through the UD flexural rigidity holding layer 2 or theUD compressive rigidity holding layer 3 (0° layer or 90° layer), andmoreover plain weave fabric layers 21 (e.g. two or three layers) areformed through or not through the 0° layer or layers 2 or 90° layer orlayers 3 (e.g. 1 to 2 layer or layers). The plain weave fabric layer 21is a layer wound and cured so that warps becomes parallel with thelongitudinal direction of a shaft (therefore, wefts become vertical tothe longitudinal direction), which is a plain weave fabric layer 21 forholding the flexural rigidity and/or compressive rigidity so as to carryon flexural rigidity and compressive rigidity holding functions.

One or more UD flexural rigidity holding layer or layers (0° layer orlayers) 1 is or are further formed on the plain weave fabric layer 21.

In the case of still another embodiment shown in FIG. 5, one or moreplain weave fabric layer or layers 11 (e.g. two or three layers) forholding torsional rigidity is or are formed. One or more UD torsionalrigidity holding layer or layers 10 is or are formed on the plain weavefabric layer or layers 11, and moreover the triaxial fabric layer 12 isformed and the flexural rigidity and/or compressive rigidity holdingplain weave fabric layers or layer 21 are or is formed through the 0°layer 2 or 90° layer 3. The UD flexural rigidity holding layer or layers10 is or are formed on the plain weave fabric layers or layer 21.

In the case of the golf club shaft, the above plain weave fabric andplain weave prepreg are effectively used for the plain weave fabriclayers 11 and 21.

In the case of the preferable embodiment shown in FIG. 6, the plainweave fabric layer 11 is formed on the UD torsional rigidity holding 10and the triaxial fabric layer 12 is formed adjacently to the layer 11.The UD flexural rigidity holding layer 2 is further formed on thetriaxial fabric layer 12.

The triaxial fabric 5 has the first warp 52 inclined from the weft 51and the second warp 53 diagonally crossed with the warp 52. These weft51, warp 52, and warp 53 are woven by alternately passing throughupsides and downsides of yarns.

It is preferable that the angle θ formed between the weft 52 and warp 53ranges between 25 and 75°. When the angle deviates from the rangebetween 25 and 75°, the isotropy of triaxial weave may be lost and theform retention characteristic may be deteriorated. It is more preferablethat the angle ranges between 50 and 70°. Typically, a fabric ispreferable which is obtained by knitting yarns in which warp 51 andwefts 52 and 53 mutually form approx. 60°.

Though the warp 51 and wefts 52 and 53 generally use carbon fiber thesame as the case of a plain weave fabric, it is also possible to use oneof alumina fiber, aramid fiber, silicon carbide fiber, amorphous fiber,and glass fiber. That is, the kind of a yarn is not basicallyrestricted. Moreover, carbon fiber includes the pitch type and pan typeboth of which can be used. It is allowed that these fibers are differentfrom each other in physical property and moreover different from eachother in physical property such as tensile strength or tensile elasticmodulus even in the same fiber.

It is preferable that the above triaxial fabric is formed between 32 and64 gauge. A triaxial fabric out of the above range may deteriorate theperformance of a golf club shaft. In the case of a triaxial fabric of 32gauge, the interval dx between the wefts 51 is 1.80 mm and the intervaldy between intersections of the warps 52 and 53 is 2.04 mm. In the caseof 64 gauge, the dx is 0.90 mm and dy is 1.04 mm.

It is preferable that the thickness of the above prepreg is 0.4 mm orless. When the thickness exceeds 0.4 mm, 1 ply becomes too thick and asufficient fiber density (thread count) may not be obtained or theworkability of the prepreg may be deteriorated because it is difficultto wind the prepreg on a shaft.

Moreover, it is preferable that the weight of the prepreg is 350 g/m² orless. When the weight exceeds 350 g/m², resin is extremely jammed intoweave patterns and the prepreg may become extremely thick. It ispreferable that the resin quantity of the prepreg ranges between 25 and50 wt %. When the resin quantity is 25 wt % or less, it may not bepossible to manufacture a preferable shaft because the resin quantity istoo little. However, when the resin quantity exceeds 50 wt %, theoutside diameter of a shaft may become extremely large.

In the case of an embodiment of the present invention, a UD flexuralrigidity holding layer 2 or UD compressive rigidity holding layer 3formed by a 0′ layer or 90° layer is set between a plain weave fabriclayer 11 and a triaxial fabric layer 12 (that is, between fabriclayers). Or, a UD torsional rigidity holding layer 10 is set betweenthem. The above configuration is used to prevent the fabric layers 11and 12 from directly contacting with each other. When the fabric layers11 and 12 directly contact with each other, a resin quantity becomesinsufficient, the peeling strength between the layers becomesinsufficient, and a displacement may occur between the layers. Toprevent the above troubles, a 0° layer or 90° layer is set. It is amatter of course that the 0° layer holds a flexural rigidity and the 90°layer holds a compressive rigidity. Moreover, in the case of anotherembodiment, it is possible to set the plain weave fabric layer 11 andtriaxial fabric layer 12 so as to contact with each other (that is, toset fabric layers so as to contact with each other).

In the case of still another embodiment of the present invention, a UDflexural rigidity holding layer 2 is formed on fabric layers 11 and 12or a fabric layer 21 as shown in FIGS. 3 to 6. The UD flexural rigidityholding layer 2 constitutes the outermost surface layer of a shaft.Moreover, in the case of still another preferred embodiment, atransparent resin layer not including reinforcing fibers is formed onthe UD flexural rigidity holding layer 2 or fabric layers 11, 12, and21. After setting the UD flexural rigidity holding layer 2 and/or thetransparent resin layer, the embodiment is formed into a product bypolishing and smoothing the surface of the UD flexural rigidity holdinglayer 2 on the outermost surface layer and then, applying painting andprinting to the surface, and forming a transparent surface layer.

In the case of the above embodiment, the triaxial fabric layer 12 andthe plain weave fabric layer 11 are formed over the entire length of theshaft. However, it is also possible to form a part of the layer 12and/or the layer 11 at the chip side and/or bat side. Moreover, it ispossible to form a part of the layer 12 and/or the layer 11 at the chipside and/or bat side or independently at the central portion of theshaft

Examples 1 and 2

A golf club shaft is manufactured by using the plain fabric shown inFIG. 2. The golf club shaft is formed by winding a plain weave prepreg(resin quantity=40%; elastic modulus of reinforcing fiber=24 t) of thepresent invention up to 3 plies, UD prepregs aligned in the directionvertical to the longitudinal direction of the shaft (for each of theseprepregs: resin quantity=40%; elastic modulus of reinforcing fiber=24 t)by 1 ply, and a flexural rigidity holding UD prepreg having reinforcingfibers aligned parallel with the longitudinal direction of the shaft(resin quantity=24%; elastic modulus of reinforcing fiber=30 t) up to 2plies on a mandrel and curing them. The plain weave prepreg is woundlike a shaft so that the warp 51 and weft 52 of the plain weave fabricare mutually crossed at an angle θ of approx. 45° from the longitudinaldirection of the shaft (example 1).

Moreover, a plain weave prepreg (resin quantity=40%; elastic modulus ofreinforcing fiber-24 t) of the present invention is wound like a shaftup to 3 plies so that the warp 51 and weft 52 of the plain weave fabricare mutually crossed at an angle θ of approx. 45° from the longitudinaldirection of the shaft (refer to the arrow in FIG. 1). Then, a plainweave prepreg (resin quantity=40%; elastic modulus of reinforcingfiber=24 t) is wound by 1 ply so that the warp 51 or weft 52 becomesparallel with the longitudinal direction of the shaft (or weft or warpbecomes vertical to longitudinal direction of shaft). Moreover, aflexural rigidity holding CD prepreg (resin quantity=24%; elasticmodulus of reinforcing fiber=30 t) having reinforcing fibers aligned inparallel with the longitudinal direction of the shaft is wound on amandrel by 2 plies and cured to form a golf club shaft (example 2).

Moreover, for comparison, a golf club shaft is manufactured by usingthree UD torsional rigidity holding layers (UD prepreg 41=3 plies and UDprepreg 42=3 plies) (resin quantity=40%; elastic modulus of reinforcingfiber=24 t) instead of a plain weave fabric layer, UD prepreg in whichreinforcing fibers are aligned in parallel with a shaft by 1 ply, UDprepregs aligned in the direction vertical to the longitudinal directionof the shaft (for each of the above prepregs, resin quantity=40%;elastic modulus of reinforcing fiber-24 t) by 1 ply, and a UD flexuralrigidity holding layer (resin quantity=24%; elastic modulus ofreinforcing fiber=30 t) up to 2 plies (comparative example 1).

A carbon fiber yarn (3 K) is used as reinforcing fibers of each layer.Moreover, warps and wefts of a plain weave fabric respectively use acarbon fiber. The thickness of each of the warps and wefts is 3 K andthe thread count of each of the warps and wefts is 4.9 yarns/cm.Moreover, when using a plain weave prepreg, the thickness is 0.22 mm andthe weight is 328 g/m².

Characteristics of the above golf club shaft are shown below.

TABLE 1 Comparative Example 1 Example 2 example, Length 46 in 46 in 46in Weight 67.2 g 67.9 g 67.8 g Torque 5.8° 5.65° 5.67° Frequency 245 cpm244 cpm 244 cpm

Golf club shafts (each shaft length is 45 in) are respectively formed bysetting the same grip of 51 g and the same head of 194 g to make a robothit golf balls under the same condition. The robot is set so thatpositions of rbi to heads become the same for all clubs and the headspeed becomes 40 m/s.

As a result of hitting 100 golf balls at the center of the head of agolf club using the shaft of the example 1 of the present invention,dropping points (carries) of the balls are approx. 198.7 yd±3.75 yd asdifferences in the back and forth direction (carry) and ±5.5 yd asdifferences in the transverse direction. Moreover, as a result ofhitting 100 golf balls by shifting the hitting position of the head by10 mm to the toe side, dropping points (carries) of the balls areapprox. 196.4 yd±3.9 yd as differences in the back and forth direction(carry) and ±4.5 yd as differences in the transverse direction anddifferences of carries are the same as the case of hitting balls at thecenter of the head. However, differences in the transverse directionwhen shifting the hitting position by 10 mm are smaller.

However, when hitting 100 golf balls by the head of a golf club usingthe shaft of the example 2 of the present invention, dropping points(carries) of the balls are approx. 197.9 yd±2.95 yd as differences inthe back and forth direction (carry) and ±4.1 yd as differences in thetransverse direction. Moreover, as a result of hitting 100 golf balls byshifting the hitting position of the head by 10 mm to the toe side,dropping points of the balls are approx. 193.1 yd±3.55 yd as differencesin the back and forth direction (carry) and ±3.6 yd as differences inthe transverse direction. Though differences of carries are the same asthe case of hitting balls at the center of the head, differences in thetransverse direction when shifting the hitting position of the head by10 mm to the toe side are smaller.

In the case of a golf club formed by a conventional shaft, however,dropping points of balls are approx. 193.7 yd±5.7 yd as differences inthe back and forth direction (carry) and ±5.85 yd as differences in thetransverse direction when hitting the balls at the center of the head ofthe club. Moreover, as a result of hitting golf balls by shifting thehitting position of the head by 10 mm to the toe side, dropping pointsof the balls are approx. 193.7 yd±9.25 yd as differences in the back andforth direction (carry) and ±4.5 yd as differences in the transversedirection.

That is, in the case of the example 1, it is found that differences inthe back and forth direction are small compared to the case ofcomparative example 1 and the example 1 has preferable distancestability. Because the golf club shaft of the example 1 has differencesin the transverse direction smaller than those of a conventional onethough the shaft of the example 1 has a torque larger than that of theconventional one and thereby, the shaft of the example 1 can be used asa stable golf club shaft. However, as a result of comparing the example2 with the comparative example 1, it is found that the shaft of theexample 2 has an extreme stability in both back and forth and transversedirections. Moreover, golf shafts of the present invention respectivelyhave a comparatively slow response characteristic and, easily meetballs, and thereby the controllability is improved.

From the above results, it is considered that movements of a warp andweft are small because a plain weave fabric is woven. For this reason,stability is generated in a distance and direction because displacementsbetween plain weave fabric layers and between a plain weave fabric layerand a flexural rigidity layer decrease, and a torsional rigidity isimproved because movements of a warp and weft are small. According tothese results, it is found that it is possible to manufacture a clubparticularly useful for an iron club for which stabilities of a distanceand direction are requested. Moreover, because a plain weave fabriclayer has a large isotropy, the feeling same as that of steel can beobtained.

Example 3

A golf club shaft is manufactured by using the plain weave fabric shownin FIG. 2. A golf club shaft is formed by winding a plain weave prepreg(resin quantity=40%; elastic modulus of reinforcing fiber=24 t) up to 3plies, a UD prepreg obtained by mutually overlapping an incline prepreg(resin quantity=40%; elastic modulus of reinforcing fiber=24 t) in whichreinforcing fibers are diagonally set in a predetermined direction andan incline prepreg (resin quantity=40%; elastic modulus of reinforcingfiber=24 t) in which reinforcing fibers are set in the directionopposite to the predetermined direction up to 3 plies (3×2 prepregs areused), and a conventional flexural rigidity holding UD prepreg (resinquantity=24%; elastic modulus of reinforcing fiber (carbon fiber)=30 t)having reinforcing fibers aligned in parallel with the longitudinaldirection of the shaft up to 4 plies on a mandrel and curing them.

Moreover, the plain weave prepreg is wound like a shaft so that the warp51 and weft 52 are mutually crossed at an angle θ of 45° from thelongitudinal direction of the shaft (refer to the arrow in FIG. 2).

Reinforcing fibers of each layer use carbon fibers. All warps and weftsof a plain weave fabric use carbon fibers. The thickness of each warpand that of each weft are 3 K and thread counts of warps and wefts are4.9 yarns/cm respectively. Moreover, when forming a prepreg, thethickness is 0.22 mm and the weight is 328 g/cm².

Moreover, for comparison, a golf club shaft (comparative example 2) ismanufactured by using six conventional UD torsional rigidity holdinglayers (UP prepreg 41=6 plies and UD prepreg 42=6 plies) (resinquantity=40%; elastic modulus of reinforcing fiber=24 t) and a UDflexural rigidity holding layer (resin quantity=24%; elastic modulus ofreinforcing fiber=30 t) up to 4 plies. A yarn of reinforcing fibers usescarbon fibers (3 K).

Characteristics of the above golf club shaft are shown below.

TABLE 2 Example 3 Comparative example 2 Length 46 in 46 in Weight 98.4 g99.3 g Torque 3.2° 2.8° Frequency 264 cpm 264 cpm

Golf clubs are formed by setting the same grip of 51 g and the same headof 194 g to the golf clubs (each shaft length is 45 in) to make a robothit golf balls under the same condition. The robot is set so thatpositions of rbi to heads become the same for all clubs and the headspeed becomes 40 m/s.

As a result of hitting 100 golf balls at the center of the head of agolf club using the shaft of the present invention, dropping points(carries) of the balls are approx. 189 yd±4 yd as differences in theback, and forth direction (carry) and ±4.7 yd as differences in thetransverse direction. Moreover, as a result of hitting 100 golf balls byshifting the hitting position of the head by 10 mm to the toe side,dropping points (carries) of the balls are 188.7 yd±4 yd as differencesin the back and forth direction (carry) and ±8 yd as differences in thetransverse direction. In this case, the differences of carry are thesame as the case of hitting balls at the center of the head.

However, in the case of the golf club using a conventional shaft,dropping points of balls are approx. 188 yd±6 yd as differences in theback and forth direction (carry) and ±5 yd as differences in thetransverse direction. Moreover, as a result of hitting 100 balls byshifting the hitting position to the toe side by 10 mm, dropping pointsof the balls are approx. 185 yd±6.6 yd as differences in the back andforth direction (carry) and +10 yd as differences in the transversedirection.

That is, the golf club shaft of the present invention shows a verypreferable distance stability compared to a conventional case. Moreover,it is found that both the golf club shafts of the present invention andthe comparative example respectively have a comparatively slow responsecharacteristic, easily meet balls, and thereby the controllability isimproved. Furthermore, because the golf club shaft of the example 3 hassmall transverse-directional differences and therefore, the golf clubshaft can be obtained as a stable golf club shaft.

The following are results of measuring characteristics of the golf clubshaft of the present invention and the conventional golf club shaft.

TABLE 3 Example 3 Conventional shaft Improvement rate Backspin2,600-2,700 Approx. 3,000 Decrease of 10% Lofting angle Decrease of 30%in fluctuation fluctuation (Center) Carry 189 ± 4 185 ± 6.6 Decrease of40% in fluctuation (To toe side by 10 mm)

From the above results, it is considered that because a plain weavefabric is plainly woven, movements of a warp and weft are small, anddisplacements between plain weave fabric layers and between a plainweave fabric layer and a flexural rigidity layer are small andtherefore, distance and direction are stabilized and torsional rigidityis improved because movements of a warp and a weft are small. Thereby,it is found that it is possible to manufacture a club particularlyuseful for an iron club for which stabilities of distance and directionare requested. Moreover, because a plain weave fabric layer has a largeisotropy, the feeling same as that of steel can be obtained.

From the above results, it is found that in the case of the golf clubshafts of the examples 1 and 3 of the present invention, differences inthe back and forth direction (carry) are small and the distancestability is increased compared to a conventional case. Moreover, in thecase of the example 2, it is found that not only the distance stabilityis increased but also differences in the transverse direction areextremely increased and therefore, the example 2 is a more preferablegolf club shaft. From these results, it is found that the golf clubshaft of the example 2 is most suitable as a shaft for an iron club forwhich small differences in the back and forth or transverse directionare requested.

As described above, according to a golf club shaft of the presentinvention, a plain weave fabric layer formed by impregnating the plainweave fabric with a thermosetting resin and curing the fabric is used asa torsional rigidity holding layer. The plain weave fabric is woven bywarps and wefts and movements of yarns are restricted. Therefore,because a warp demonstrates a resistance against a longitudinal forceand a weft demonstrates a resistance against a transverse force, it ispossible to effectively retrain a deformation or a displacement betweenthermosetting-resin layers. Therefore, it is possible to restrain adisplacement between layers at the time of a shot and the golf clubshaft can be formed into a golf club shaft having a stability and afeeling same as that of a steel shaft.

Examples 4 and 5

A golf club shaft is manufactured by using the plain weave fabric and atriaxial fabric shown in FIGS. 2 and 7. A golf club shaft is formed bymutually overlapping an incline prepreg 41 in which reinforcing fibersare diagonally set in a predetermined direction and an incline prepreg42 in which reinforcing fibers are set in the direction opposite to thepredetermined direction as an innermost torsional rigidity holding layer1 and successively winding two prepreg sheets 4 in which reinforcingfibers are diagonally crossed (referred to as UD torsional rigidityholding layer) (prepreg is 22 plies), plain weave fabric prepreg sheetsup to 3 plies, a triaxial fabric prepreg up to 1 ply, and a 0° layerprepreg up to 3 plies on a mandrel, curing the thermosetting resin ofprepregs, and polishing the surface of the shaft (example 4; refer toFIG. 6).

The resin quantity of the plain weave fabric prepreg is 40% and that ofthe 0° layer prepreg is 25%. The plain weave fabric prepreg is woundlike a shaft so that a warp and a weft are mutually crossed at an angleθ of approx. 45° from the longitudinal direction of the shaft. Carbonfibers are used for reinforcing fibers of the UD torsional rigidityholding layer, 0° layer, and plain weave fabric layer. The thickness ofeach warp and that of each weft of the plain weave fabric layer are 3 Krespectively and the thread count of warps and that of wefts are 4.9yarns/cm respectively. Moreover, the thickness of a prepreg is 0.22 mmand the total weight of prepreg is 328 g/m².

Furthermore, the thickness of warps and that of a weft of the triaxialfabric are set to 1 K respectively and the angle of a warp from a weftis set to 60°. A prepreg obtained by impregnating the triaxial fabric(32 gauge) with 40% of a resin is used. Moreover, the thickness of aprepreg is 0.175 mm and the total weight is 122 g/m². The prepreg iswound so as to wefts are directed to be vertical (90° direction) to theshaft.

A golf club shaft (example 5; refer to FIG. 1) is manufactured which isformed by using two of the above UD torsional rigidity holding layer,three plain weave fabric layers, and three flexural rigidity holdinglayers (0° layers) and moreover, for comparison, a golf club shaft(comparative example 3) is manufactured which is formed by using four ofthe above UD torsional rigidity holding layer and three flexuralrigidity holding layers (0° layers).

45 inch Golf clubs are prepared by setting a head and a grip to theabove golf shafts A (example 4), B (example 5), and C (comparativeexample 3).

TABLE 4 Frequency Club weight Head weight Shaft weight Grip weight A 254321.9 g 194.9 g 71.2 g 50.7 g B 255 323.3 g 194.6 g 72.1 g 50.5 g C 255325.7 g 194.0 g 74.7 g 50.6 g

In the above Table 4, the unit of the frequency is CPM. For torques ofshafts, A is 4.26°, B is 3.98°, and C is 4.07°.

Golf balls are hit by a robot under the same condition by using theabove three golf clubs. The robot is set so that positions of rbi toheads become the same for all clubs and the head speed becomes 42 m/s.

As a result of making the robot hit 100 balls at the center of the headof the golf club A using a shaft of the present invention, droppingpoints (carries) of the balls are approx. 205 yd±3 yd as differences inthe back and forth direction (carry) and ±4.25 yd as differences in thetransverse direction. Moreover, as a result of making the robot hit 100balls by shifting the hitting position to the toe side by 10 mm,dropping points of the balls are approx. 200.7 yd±3 yd as differences inthe back and forth direction (carry) and ±3.75 yd as differences in thetransverse direction.

In the case of the golf club B, as a result of hitting balls at thecenter of the head, dropping points of the balls are approx. 206±3.75 ydas differences in the longitudinal direction (carries) and ±5.0 yd asdifferences in the transverse direction. Moreover, as a result of makingthe robot hit 100 balls by shifting the hitting position to the toe sideby 10 mm, dropping points of the balls are approx. 200.6 yd±4.5 yd asdifferences in the back and forth direction and ±2.75 yd as differencesin the transverse direction.

However, in the case of the golf club C, as a result of hitting balls atthe center of the head, dropping points of balls are approx. 206 yd±5.7yd as differences in the back and forth direction (carry) and ±6.5 yd asdifferences in the transverse direction. Moreover, as a result ofhitting 100 balls by shifting the hitting position to the toe side by 10mm, dropping points of the balls are approx. 202.7 yd±5.25 yd asdifferences in the back and forth direction and ±4.0 yd as differencesin the transverse direction.

That is, the golf club shaft A of the present invention shows apreferable distance stability compared to the golf clubs B and C.Particularly in compare with the conventional UD prepreg golf club C,the golf club shaft of the present invention has improved distance andtransverse and a stable golf club shaft can be obtained.

1. (canceled)
 2. (canceled)
 3. (canceled)
 4. (canceled)
 5. A golf clubshaft comprising a torsional rigidity holding layer made ofthermosetting resin including reinforcing fibers diagonally crossed inthe longitudinal direction of said shaft and a UD flexural rigidityholding layer made of thermosetting resin including reinforcing fibersaligned in parallel to the longitudinal direction of said shaft,characterized in that at least a part of said torsional rigidity holdinglayer includes a plain weave fabric layer obtained by winding and curinglike a shaft-shape a plain weave prepreg which lets a plain weave fabrichaving mutually woven warps and wefts impregnate with thermosettingresin in such a way that said warps and wefts are diagonally crossed inthe longitudinal direction of said shaft, and in that said plain weavelayer, UD flexural rigidity holding layer, compressive rigidity holdinglayer, and flexural rigidity holding layer are laminated in order.
 6. Agolf club shaft comprising a torsional rigidity holding layer made ofthermosetting resin including reinforcing fibers diagonally crossed inthe longitudinal direction of said shaft and a UD flexural rigidityholding layer made of thermosetting resin including reinforcing fibersaligned in parallel to the longitudinal direction of said shaft,characterized in that at least a part of said torsional rigidity holdinglayer includes a plain weave fabric layer obtained by winding and curinglike a shaft-shape a plain weave prepreg which lets a plain weave fabrichaving mutually woven warps and wefts impregnate with thermosettingresin in such a way that said warps and wefts are diagonally crossed inthe longitudinal direction of said shaft, in that the torsional rigidityholding layer of the plain weave fabric layer and a plain weave fabriclayer for holding flexural rigidity and/or compressive rigidity areformed by winding like a shaft-shape the plain weave prepreg in such amanner that the wefts or the warps are parallel with the longitudinaldirection of the shaft and by curing the prepreg, and in that said plainweave fabric layer, plain weave fabric layer for flexural rigidity andcompressive rigidity and UD flexural rigidity holding layer arelaminated in order.
 7. A golf club shaft comprising a torsional rigidityholding layer made of thermosetting resin including reinforcing fibersdiagonally crossed in the longitudinal direction of said shaft and a UDflexural rigidity holding layer made of thermosetting resin includingreinforcing fibers aligned in parallel to the longitudinal direction ofsaid shaft, characterized in that at least a part of said torsionalrigidity holding layer includes a plain weave fabric layer obtained bywinding and curing like a shaft-shape a plain weave prepreg which lets aplain weave fabric having mutually woven warps and wefts impregnate withthermosetting resin in such a way that said warps and wefts arediagonally crossed in the longitudinal direction of said shaft, and inthat said plain weave fabric layer, UD torsional rigidity holding layer,and UD flexural rigidity holding layer are laminated in order. 8.(canceled)
 9. (canceled)
 10. (canceled)
 11. (canceled)
 12. (canceled)13. (canceled)
 14. (canceled)
 15. A golf club shaft, comprising atorsional rigidity holding layer made of thermosetting resin includingreinforcing fibers diagonally crossed in the longitudinal direction ofsaid shaft and a UD flexural rigidity holding layer made ofthermosetting resin including reinforcing fibers aligned in parallel inthe longitudinal direction of said shaft, characterized in that saidtorsional rigidity holding layer includes a plain weave fabric layerformed by winding like a shaft-shape a plain weave prepreg obtained byimpregnating a plain weave fabric having mutually-woven warps and weftswith thermosetting resin and curing the prepreg in such a way that saidwarps and wefts are diagonally crossed in the longitudinal direction ofsaid shaft, and a triaxial fabric layer formed by winding like ashaft-shape a triaxial fabric prepreg obtained by impregnating atriaxial fabric which has first warps inclined to wefts and second warpsdiagonally crossing with the first warps and has a structure where thesewarps and wefts are woven by alternately passing through upsides anddownsides of yarns with thermosetting resin in such a way that saidwefts become parallel with or vertical to the longitudinal direction ofsaid shaft and curing the prepreg.
 16. The golf club shaft according toclaim 15, further comprising a UD compressive rigidity holding layer.17. The golf club shaft according to claim 16, wherein the UD flexuralrigidity holding layer and/or the UD compressive rigidity holding layerare/is provided between said triaxial fabric layer and said plain weavefabric layer.
 18. The golf club shaft according to claim 15,characterized in that said UD torsional rigidity holding layer, plainweave fabric layer, and UD flexural rigidity holding layer or said UDcompressive rigidity holding layer, triaxial fabric layer, and UDflexural rigidity holding layer are laminated in order.
 19. (canceled)20. The golf club shaft according to claim 15, characterized in thatplain weave fabric layer for flexural rigidity and/or compressiverigidity holding is included which is obtained by winding said warps orwefts like a shaft-shape and curing in such a way that the warps orwefts become parallel with in the longitudinal direction of said shaft.21. The golf club shaft according to claim 20, characterized in that thefollowing layers are laminated in order; said UD torsional rigidityholding layer, UD compressive rigidity holding layer, plain weave fabriclayer, UD compressive rigidity holding layer, triaxial fabric layer, UDcompressive rigidity holding layer, plain weave fabric layer forflexural rigidity and/or compressive rigidity holding and UD flexuralrigidity holding layer.
 22. The golf club shaft according to claim 20,characterized in that the following layers are laminated in order; saidUD flexural rigidity holding layer or UD compressive rigidity holdinglayer, UD torsional rigidity holding layer, plain weave fabric layer, UDflexural rigidity holding layer or UD compressive rigidity holdinglayer, triaxial fabric layer, UD flexural rigidity holding layer or UDcompressive rigidity holding layer, plain weave fabric layer forflexural rigidity and/or compressive rigidity and UD flexural rigidityholding layer.
 23. The golf club shaft according to claim 20,characterized in that the following layers are laminated in order; saidplain weave fabric layer, UD torsional rigidity holding layer, triaxialfabric layer, UD flexural rigidity holding layer or UD compressiverigidity holding layer, plain weave fabric layer for flexural rigidityand/or compressive rigidity, and UD flexural rigidity holding layer. 24.The golf club shaft according to claim 15, characterized in that athread count of said plain weave fabric is 4 yarns/cm or more.
 25. Thegolf club shaft according to claim 15, characterized in that thethickness of a yarn of said plain weave fabric is 3 K or less.
 26. Thegolf club shaft according to claim 15, characterized in that the weightof said plain weave prepreg is 400 g/cm² or less and the thickness ofthe same is 0.3 mm or less.
 27. The golf club shaft according to claim15, characterized in that the resin quantity of said plain weave prepregranges between 25 and 40 wt %.
 28. The golf club shaft according toclaim 15, characterized in that the angle between the warp and the weftof said plain weave fabric is 90°.
 29. The golf club shaft according toclaim 15, characterized in that in the case of said plain weave fabric,warps and wefts are wound so as to be approx (original): 45° to thelongitudinal direction of said shaft each other.
 30. The golf club shaftaccording to claim 15, characterized in that said triaxial fabric are 32or 64 gauges.
 31. The golf club shaft according to claim 15,characterized in that the weight of the prepreg of said triaxial fabricis 350 g/m² or less and the thickness of the same is 0.4 mm or less. 32.The golf club shaft according to claim 15, characterized in that theresin quantity of the prepreg of said triaxial fabric ranges between 25and 50 wt %.
 33. The golf club shaft according to claim 15,characterized in that the angle between warps and wefts of said triaxialfabric is 60°.